Calipers



(N0 Modem R. H. BROWN.

GALIPERS.

Patented Nov. 20, 1883.

Jim?

UNITED STATES PATENT OFFIC REUBEN H. BROW'N, OF NEW HAVEN, CONNECTICUT.

GALlPERS.

SPECIFICATION forming part of Letters PatentNo. 288,771, dated November 20, 1883,

Application filed May 3, 1883. (No model.)

To all whom it may concern.-

Be it known that I, REUBEN H. BROWN, of New Haven, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Calipers, of which the following is a specification, reference being had to the accompanying drawings.

My invention is designed for use with ordinary measuring-calipers, or with that class of instruments known as micrometer-gages, and is designed to increase their effectiveness, to give them greater nicety of action, and to permit of their readjustment after their accuracy has been destroyed by wear.

Figure l is aside view of my invention, showin g its application to a micrometer-gage or calipers. Fig. 2 is an edge or end view of the same. Figs. 3 and 4 show details of the invention.

Similar letters of reference indicate similar parts in the respective views.

A. is a block, threaded to receive the screw 13. To theblock A are pivoted or hinged the legs 0 C. The lower end of the screw B is made to turn freely in ayoke, D, being secured and adjusted thereto by meansof an upper nut, a, and a lower nut, b. Each end of the yoke is slotted to permit the entry of a leg of the calipers, and provided with a roll, 0, adapted to rest upon the outer edge of a leg, and to turn freely upon its pivot c.

A spring, E, (shown detached in Fig. 3,) is clamped between the nut a and the top of the yoke D, the outer ends of the spring being free and conforming to the curve of the inner edges of the legs. The spring E acts to extend the instrument and to keep the outer edges of the legs in contact with the rolls a. A perspective view of the yoke D is shown in Fig. 4.

From the top of the block A extends a cylindrical graduated part, d. The upperportion of the screw B is provided with a cylindrical cap, F,which fits neatly over the cylindrical part d of the block. The lower end of the capF is beveled and vertically graduated to act in connection withthe graduated marks of the part (2, as in the micrometer-gage now in use. The head of the cylindrical cap F is secured to the top of the screw B by means of a screw, 6. I

On turning the cylindrical cap F the screw Bis revolved and the yoke D elevated, the spring E expanding the instrument. The rolls a slide upon the outer edges of the legs 0 C, said edges being so curved or shaped that the points ff of the legs are moved in a perfectly regular manner. To contract the instrument the cap F must be revolved in the opposite direction, and the rolls 0, sliding upon the curved outer edges of the legs, will cause the legs to approach. Should the points f f become. worn, the cap F must be turned until the points meet. The screw 6 must now beloosened and the cap F turned until its zeropoint corresponds with that of the graduated cylindrical portion (Z of the block A. On tightening the screw 6 the instrument is read justed and again in perfect order.

I claim as my inventionl. The combination, in calipers, of athreaded rod having its end turning in a yoke, a nut traveling on said threaded rod and having legs pivoted thereto bearing against rolls lo cated in the outer ends of the yoke, and a freeended spring clamped to the yoke and having its free ends curved to conform to the inner contour of the legs and exerting an unvarying pressure on the same, irrespective of their degree of adjustment, substantially as set forth.

2. The combination, in calipers or micrometer-gages, of a block or nut having a graduated cylindrical extension, a screw, a cylindrical graduated cap secured to the screw and fitting over the said cylindrical extension, legs piv oted or hung to said block, a yoke connected to the lower end of the screw, and in which said screw freely turns, said yoke being stationary with respect to said nut and legs, afree-ended spring for expanding the legs, and rolls supported in the respective ends of the yoke and resting upon the outer edges of the legs, substantially as set forth.

In testimony whereof I hereunto set my handand seal in the presence of two witnesses.

REUBEN H. BROWN. [L. s}

Witnesses: I

A. O. DEPEW, J our: N. AUSTIN. 

